Currently, 3G (or 3.5G) cellular phone systems employing a CDMA (Code Division Multiple Access) scheme are widely used.
In recent years, an OFDM (Orthogonal Frequency Division Multiplexing) scheme to transmit data in parallel by using multiple subcarriers orthogonal to each other has drawn attention as a new communication scheme. The OFDM scheme is able to exert higher communication performances than the CDMA scheme, and is therefore used for 4G (or 3.9G) cellular phone systems and the like.
Since installation of radio base stations supporting a new communication scheme in a radio communication system such as a cellular phone system gradually advances, it is expected that radio terminals supporting both of the CDMA scheme and the OFDM scheme will be widely used in a transitional period from the third generation to the fourth generation.
Conventionally, a radio terminal supporting two communication schemes (so-called a dual terminal) switches a communication scheme used for radio communication with a radio base station (hereinafter referred to as a used communication scheme) by using the following method. For example, the dual terminal compares reception powers measured for the respective communication schemes and switches the used communication scheme from the communication scheme with lower reception power to the communication scheme with higher reception power (see Patent Document 1).